Calculate the Trump Tax
Pyth, 32 bytes
*c@_j270588 6shS,6ca0tQ*12500E20

Test suite.

2 = single
4 = married
3 = head of household

Some ridiculous encodings:
Previous 6-byte:
JQ.vCE

Test suite.

74892585093965377905208487730659359537614936740881725652453863997600444976 = single
74892585093965377905208487730659359537614936740881725652668629404830675504 = married
74892585093965377905208487730659359537614936740881725652526490039149933104 = head of household

Encodes the whole program into the second number.
Previous 24-byte:
JjE^T6*c@tJhS,7shctQhJ20

Test suite.

25000000000000000000002000004000004000004000004000005 = single
50000000000000000000002000004000004000004000004000005 = married
37500000000000000000002000004000004000004000004000005 = head of household

Previous 26-byte:
*c@_j270588 6shS,6ca0tQE20

Test suite.

25000 = single
50000 = married
37500 = head of household