  Single phonon excitations, with energies in the $1-100 \, \text{meV}$ range,
are a powerful probe of light dark matter (DM). Utilizing effective field
theory, we derive a framework to compute DM absorption rates into single
phonons starting from general DM-electron, proton, and neutron interactions. We
apply the framework to a variety of DM models: Yukawa coupled scalars,
axionlike particles (ALPs) with derivative interactions, and vector DM coupling
via gauge interactions or Standard Model electric and magnetic dipole moments.
We find that GaAs or $\text{Al}_2\text{O}_3$ targets can set powerful
constraints on a $U(1)_{B-L}$ model, and targets with electronic spin ordering
are similarly sensitive to DM coupling to the electron magnetic dipole moment.
Lastly, we make the code, \textsf{PhonoDark-abs} (an extension of the existing
\textsf{PhonoDark} code which computes general DM-single phonon scattering
rates), publicly available.
