diff --git a/server/src/index.js b/server/src/index.js
index 2d58a68..7220617 100644
--- a/server/src/index.js
+++ b/server/src/index.js
@@ -5,6 +5,7 @@ const path = require('path');
 const healthRouter = require('./routes/health');
 const configRouter = require('./routes/config');
 const billsRouter = require('./routes/bills');
+const paychecksRouter = require('./routes/paychecks');
 const db = require('./db');
 
 const app = express();
@@ -17,6 +18,7 @@ app.use(express.json());
 app.use('/api', healthRouter);
 app.use('/api', configRouter);
 app.use('/api', billsRouter);
+app.use('/api', paychecksRouter);
 
 // Serve static client files in production
 const clientDist = path.join(__dirname, '../../client/dist');
diff --git a/server/src/routes/paychecks.js b/server/src/routes/paychecks.js
new file mode 100644
index 0000000..76e801e
--- /dev/null
+++ b/server/src/routes/paychecks.js
@@ -0,0 +1,235 @@
+const express = require('express');
+const router = express.Router();
+const { pool } = require('../db');
+
+const CONFIG_KEYS = [
+  'paycheck1_day',
+  'paycheck2_day',
+  'paycheck1_gross',
+  'paycheck1_net',
+  'paycheck2_gross',
+  'paycheck2_net',
+];
+
+const CONFIG_DEFAULTS = {
+  paycheck1_day: 1,
+  paycheck2_day: 15,
+};
+
+async function getConfig() {
+  const result = await pool.query(
+    'SELECT key, value FROM config WHERE key = ANY($1)',
+    [CONFIG_KEYS]
+  );
+  const map = {};
+  for (const row of result.rows) {
+    map[row.key] = row.value;
+  }
+  const config = {};
+  for (const key of CONFIG_KEYS) {
+    const raw =
+      map[key] !== undefined
+        ? map[key]
+        : CONFIG_DEFAULTS[key] !== undefined
+        ? String(CONFIG_DEFAULTS[key])
+        : null;
+    config[key] = raw !== null ? Number(raw) : null;
+  }
+  return config;
+}
+
+// Pad a number to two digits
+function pad2(n) {
+  return String(n).padStart(2, '0');
+}
+
+// Generate (upsert) paycheck records for the given year/month.
+// Returns the two paycheck rows with their assigned bills.
+async function generatePaychecks(year, month) {
+  const config = await getConfig();
+
+  const client = await pool.connect();
+  try {
+    await client.query('BEGIN');
+
+    const paycheckIds = [];
+
+    for (const num of [1, 2]) {
+      const day = num === 1 ? config.paycheck1_day : config.paycheck2_day;
+      const gross = num === 1 ? config.paycheck1_gross : config.paycheck2_gross;
+      const net = num === 1 ? config.paycheck1_net : config.paycheck2_net;
+      const payDate = `${year}-${pad2(month)}-${pad2(day)}`;
+
+      // Upsert paycheck record
+      const pcResult = await client.query(
+        `INSERT INTO paychecks (period_year, period_month, paycheck_number, pay_date, gross, net)
+         VALUES ($1, $2, $3, $4, $5, $6)
+         ON CONFLICT (period_year, period_month, paycheck_number)
+         DO UPDATE SET pay_date = EXCLUDED.pay_date,
+                       gross = EXCLUDED.gross,
+                       net = EXCLUDED.net
+         RETURNING id`,
+        [year, month, num, payDate, gross || 0, net || 0]
+      );
+      const paycheckId = pcResult.rows[0].id;
+      paycheckIds.push(paycheckId);
+
+      // Fetch all active bills assigned to this paycheck number
+      const billsResult = await client.query(
+        'SELECT id FROM bills WHERE active = TRUE AND assigned_paycheck = $1',
+        [num]
+      );
+
+      // Idempotently insert each bill into paycheck_bills
+      for (const bill of billsResult.rows) {
+        await client.query(
+          `INSERT INTO paycheck_bills (paycheck_id, bill_id)
+           VALUES ($1, $2)
+           ON CONFLICT (paycheck_id, bill_id) DO NOTHING`,
+          [paycheckId, bill.id]
+        );
+      }
+    }
+
+    await client.query('COMMIT');
+    return paycheckIds;
+  } catch (err) {
+    await client.query('ROLLBACK');
+    throw err;
+  } finally {
+    client.release();
+  }
+}
+
+// Fetch both paycheck records for a month with full bill and one_time_expense data.
+async function fetchPaychecksForMonth(year, month) {
+  // Fetch paycheck rows
+  const pcResult = await pool.query(
+    `SELECT id, period_year, period_month, paycheck_number, pay_date, gross, net
+     FROM paychecks
+     WHERE period_year = $1 AND period_month = $2
+     ORDER BY paycheck_number`,
+    [year, month]
+  );
+
+  const paychecks = [];
+
+  for (const pc of pcResult.rows) {
+    // Fetch associated bills joined with bill definitions
+    const billsResult = await pool.query(
+      `SELECT pb.id AS paycheck_bill_id,
+              pb.bill_id,
+              b.name,
+              b.amount,
+              pb.amount_override,
+              CASE WHEN pb.amount_override IS NOT NULL THEN pb.amount_override ELSE b.amount END AS effective_amount,
+              b.due_day,
+              b.category,
+              pb.paid,
+              pb.paid_at
+       FROM paycheck_bills pb
+       JOIN bills b ON b.id = pb.bill_id
+       WHERE pb.paycheck_id = $1
+       ORDER BY b.due_day, b.name`,
+      [pc.id]
+    );
+
+    // Fetch one-time expenses
+    const oteResult = await pool.query(
+      `SELECT id, name, amount, paid, paid_at
+       FROM one_time_expenses
+       WHERE paycheck_id = $1
+       ORDER BY id`,
+      [pc.id]
+    );
+
+    paychecks.push({
+      id: pc.id,
+      period_year: pc.period_year,
+      period_month: pc.period_month,
+      paycheck_number: pc.paycheck_number,
+      pay_date: pc.pay_date,
+      gross: pc.gross,
+      net: pc.net,
+      bills: billsResult.rows.map((b) => ({
+        paycheck_bill_id: b.paycheck_bill_id,
+        bill_id: b.bill_id,
+        name: b.name,
+        amount: b.amount,
+        amount_override: b.amount_override,
+        effective_amount: b.effective_amount,
+        due_day: b.due_day,
+        category: b.category,
+        paid: b.paid,
+        paid_at: b.paid_at,
+      })),
+      one_time_expenses: oteResult.rows,
+    });
+  }
+
+  return paychecks;
+}
+
+// POST /api/paychecks/generate?year=&month=
+router.post('/paychecks/generate', async (req, res) => {
+  const year = parseInt(req.query.year, 10);
+  const month = parseInt(req.query.month, 10);
+
+  if (isNaN(year) || isNaN(month) || month < 1 || month > 12) {
+    return res.status(400).json({ error: 'year and month (1-12) are required query params' });
+  }
+
+  try {
+    await generatePaychecks(year, month);
+    const paychecks = await fetchPaychecksForMonth(year, month);
+    res.json(paychecks);
+  } catch (err) {
+    console.error('POST /api/paychecks/generate error:', err);
+    res.status(500).json({ error: 'Failed to generate paychecks' });
+  }
+});
+
+// GET /api/paychecks?year=&month=
+router.get('/paychecks', async (req, res) => {
+  const year = parseInt(req.query.year, 10);
+  const month = parseInt(req.query.month, 10);
+
+  if (isNaN(year) || isNaN(month) || month < 1 || month > 12) {
+    return res.status(400).json({ error: 'year and month (1-12) are required query params' });
+  }
+
+  try {
+    // Check if paychecks exist for this month; if not, auto-generate
+    const existing = await pool.query(
+      'SELECT id FROM paychecks WHERE period_year = $1 AND period_month = $2 LIMIT 1',
+      [year, month]
+    );
+
+    if (existing.rows.length === 0) {
+      await generatePaychecks(year, month);
+    }
+
+    const paychecks = await fetchPaychecksForMonth(year, month);
+    res.json(paychecks);
+  } catch (err) {
+    console.error('GET /api/paychecks error:', err);
+    res.status(500).json({ error: 'Failed to fetch paychecks' });
+  }
+});
+
+// GET /api/paychecks/months — list all generated months, most recent first
+router.get('/paychecks/months', async (req, res) => {
+  try {
+    const result = await pool.query(
+      `SELECT DISTINCT period_year AS year, period_month AS month
+       FROM paychecks
+       ORDER BY period_year DESC, period_month DESC`
+    );
+    res.json(result.rows);
+  } catch (err) {
+    console.error('GET /api/paychecks/months error:', err);
+    res.status(500).json({ error: 'Failed to fetch paycheck months' });
+  }
+});
+
+module.exports = router;