340 Madison Avenue

340 Madison Avenue has about 559,000 square feet of floor area in total, including 538,000 square feet of office, 14,000 square feet of retail and 7,000 square feet of industrial and storage space, according to NYC PLUTO 26v2. These are the city's estimates for the whole building, not space that is available.

City records list 1922 as the year built, with a major alteration recorded in 2003. The building is 22 floors tall.

City records list 9-17 East 43rd Street, 16-28 East 44th Street and 334-344 Madison Avenue on the same tax lot (BBL 1012780014) as 340 Madison Avenue. A space listed on Leasemark at any of these addresses shows up on this page.

City records give two ZIP codes for this tax lot: 10017 in NYC PLUTO 26v2 and 10173 on the Department of Finance's assessment roll. Some large New York buildings have a ZIP code of their own beside the area's, so check with the building's management which one it uses before you rely on either.

The lot is in the C5-3 zoning district. PLUTO lists a built floor area ratio (FAR) of 17.17 and a maximum commercial FAR of 15 for this lot.

The closest subway station to 340 Madison Avenue is Grand Central-42 St (the 4, 5, 6, 7 and S trains), about 450 feet away in a straight line, roughly 2 minutes on foot. The MTA lists it as an accessible station. Also nearby: 5 Av (the 7, B, D, F and M trains, connected to 42 St-Bryant Pk), 3 min walk; 47-50 Sts-Rockefeller Ctr (the B, D, F and M trains), 7 min walk. Walking times are straight-line estimates; the street route is longer.

The NYC Department of Finance's 2026/27 assessment roll lists 340 MADISON OWNER LLC as the owner of record of 340 Madison Avenue (BBL 1012780014). Big buildings are usually held through a company set up for that one property, so the name on the roll can differ from the landlord's brand or the managing agent. Deeds and mortgages for the lot are public in ACRIS, the city's property records system.

Leasemark does not have the building's tenant roster, but SEC filings name companies with offices at 340 Madison Avenue. One public company reports the address as its principal executive office: MICROALGO INC. (MLGO). 3 investment managers and funds file 13F holdings reports from the address: Charter Oak Advisors LP, Yaupon Capital Management LP and Zenkyoren Asset Management of America Inc.. Private companies do not file with the SEC, so the full list of tenants is longer, and a company can also report a building it owns.

340 Madison Avenue last sold in March 2025 for $161.3 million, according to the deed recorded with the city. The buyer of record was 340 MADISON OWNER LLC. That comes to about $289 per square foot of floor area. The deed is ACRIS document 2025031400096001 (BBL 1012780014) in the city's property records. A sale of the company that owns a building is not recorded as a deed, so it would not show there.

340 Madison Avenue reported an ENERGY STAR score of 89 for calendar year 2024 in its Local Law 84 benchmarking filing. Under Local Law 33, as amended by Local Law 95 of 2019, a score of 85 or higher earns an A, 70 to 84 a B, 55 to 69 a C and under 55 a D, so 89 earns an A. The Department of Buildings assigns the grade a building posts, so the posted label can differ if a filing was corrected. Its site energy use came to 33.5 kBtu per square foot, less than half the national median of 67.3 for a similar property. Its greenhouse gas emissions were about 2,320 metric tons of CO2e (3.59 kg per square foot).

At its 2024 energy use, 340 Madison Avenue comes to about 1,790 metric tons of CO2e a year under Local Law 97's coefficients, against a limit of 4,828 tons for 2024 to 2029 (37% of the limit), so it would owe no penalty. From 2030 the limit drops to 1,670 tons and the same energy use counts as about 1,054 tons, still under the limit. This is an estimate from the owner's 2024 benchmarking filing using the coefficients and per-use limits in the law and the Department of Buildings rule, at $268 per ton over. It is not the building's Local Law 97 report, which can count credits and deductions this estimate cannot.

In the 12 months to October 2026, the Department of Buildings issued first permits for 15 jobs at 340 Madison Avenue. In the last two years, interior work was permitted on 8 floors (floors 1, 3, 6, 9 and 19 to 22). The newest build-out, on floor 6, was first permitted in September 2026 (construction, mechanical, plumbing, sprinklers; filed cost estimate $1.2 million). A sidewalk shed permit here is active until November 15, 2026. These are the Department of Buildings' DOB NOW work permits for tax lot 1012780014. A permit is approval to do the work; it does not say who the work is for or whether it is finished.

The Department of Finance's 2026/27 assessment roll lists a taxable value of $136 million for 340 Madison Avenue. At the Class 4 rate of 10.848% (tax year 2025/26, the latest rate the Department of Finance lists), that is about $14.8 million a year, roughly $26.41 per square foot of floor area, before abatements such as ICAP. The city's property tax records for BBL 1012780014 show the actual bill.

For tax year 2026/27, the NYC Department of Finance puts the market value of 340 Madison Avenue at $302.3 million ($46.9 million of it land) and its assessed value at $136 million, the 45% of market value the city assesses for Class 4 property. The city's market value fell 8% from 2022/23 ($328 million) to 2026/27.

No space at 340 Madison Avenue is listed on Leasemark right now. Owners and brokers can list space here for free, and tenants can post a requirement to be matched when space opens up.